1. Field of the Invention
The present invention-relates to a dual wiring system, which is used for the input/output of information signal and the supply of electric power through an information line and an electric power line installed in a building structure.
2. Description of the Related Art
Along with the popularization of the Internet, it is needed to ensure accessibility to information network at various sites in building structures such as houses and office buildings. For example, Japanese Patent Early Publication No. 11-187154 discloses a multimedia wiring system, which is provided with a distributing board for controlling a power supply line and various information lines installed in a building structure in a central control manner, and a multimedia socket panel mounted in an indoor wall surface, and connected to the distributing board through the power supply line and the information lines. For example, the multimedia socket panel has power receptacles for supplying commercial power to electric appliances, sockets used to receive broadcast programs provided by, e.g., ground-based broadcasting, satellite broadcasting and cable broadcasting, and modular jacks for analog or digital line used for, telephone system and the internet. According to this multimedia wiring system, an improvement in convenience of multimedia products is achieved, and comfortable living and working environments in the information society can be obtained.
By the way, the above-mentioned multimedia socket panel is usually mounted in the wall surface during construction of the building structure, and connected to the power supply line and the information lines. This means that functions of the multimedia socket panel are substantially determined during the construction work. Therefore, after the construction work is finished, it is generally difficult to add a new function to the multimedia socket panel or exchange a part of the existing functions of the multimedia socket panel for another function. In addition, when the existing multimedia socket panel is replaced with another multimedia socket panel, a repair work is needed. However it is not easy for the general user to perform the repair work, and the cost of the repair work is a burden to the user.
In addition, in recent years, electric appliances having various functions such as an interphone device, crime-prevention device and a disaster detection device have been mounted on the wall surfaces of the building structure. With respect to the electric appliances operated according to previously installed programs, program updates are not considered in most cases. Therefore, if necessary, the user needs to replace the existing device with a new model device or another type device. On the other hand, when a program update function is built in each of the electric appliances, it will lead to a cost increase. In addition, these electric appliances often have overlapping functions. For example, each of the crime-prevention device and the disaster-detecting device has a speaker unit such that it can function by itself. However, when both of the crime-prevention device and the disaster-detecting device are installed, it is not needed that the speaker unit is built in each of those devices. Therefore, the overlapping functions are one of important problems to be solved from the viewpoint of improvement in system efficiency and cost performance.
Thus, the conventional multimedia socket panel and the electric appliances adapted in use to be mounted in the wall surfaces still have plenty of room to improve the usage efficiency of devices in a system and the cost performance of the entire system as well as function expandability and easy exchangeability.